Supplement to Model-aided Design and Integration of Functionalized Hybrid Nanomaterials for EnhancedBioremediation of PFASs Using Supercritical Fluid Chromatography/Mass Spectrometry

摘要 全氟烷基和多氟烷基物质（PFASs）的毒性引起了全球公众健康的关注， 环境持久性，以及在人类和野生动物体内的生物累积潜力。几乎每个人 接受PFAS检测的人显示，由于环境污染，他们的血液中存在可测量的PFAS水平 并继续用于消费品和工业应用。特别是饮用水似乎 这是生活在受污染场地附近的人们接触PFAS的主要来源。重要的是，一些PFAS已经 与肝损伤、发育影响和几种癌症有关（例如，肾、睾丸）。环境 迫切需要采取补救措施，但碳氟键的极端持久性阻碍了补救工作。 生物降解通常只涉及多氟全氟辛烷磺酸的非氟组分， 产生更持久和移动的更短链的全氟酸。完整的矿化 没有被证明。非生物处理技术可能更有效，但需要极高的能量 输入，降解机制知之甚少。现在急需一种治疗方法 技术具有较低的能源需求，并用于增强降解途径， 处理后不形成全氟酸的PFAS。 该提案的总体目标是制定一项创新的纳米材料生物战略， PFAS生物降解的挑战。我们的中心假设是，通过定制的纳米材料进行预处理， 促进结构多样的PFAS的转化，以实现更有效和更完全的生物降解。 我们之前的工作表明，掺入还原氧化石墨烯的官能化纳米混合催化剂 (rGO)纳米零价铁（nZVI）可以成功地引发长链PFASs的降解。在这里，我们将 利用这种非生物转化作为一种创新的预处理，以解锁PFASs的生物降解。 利用我们在分子建模和“组学”技术方面的专业知识，我们将测试和定制 微生物群落更有效地降解预处理的PFAS及其初始降解产物。所有 降解产物将通过高分辨率质谱和19F-核磁共振表征。 共振光谱来揭示这种纳米生物修复策略的机制。本研究 将通过三个相辅相成的具体目标来解决紧迫的环境污染问题： 目的1：合成多功能氧化还原活性纳米杂化材料并对其催化性能进行评价 PFAS降解性能（脱卤、长链降解为短链）。我们将 合成和表征两种多功能和分级碳-金属纳米杂化物：（i）氧化还原活性 还原氧化石墨烯纳米零价铁（rGO-nZVI）和（ii）光催化rGO-nZVI-二氧化钛 （TiO2）或rGO-nZVI-TiO2，并测试它们可以转化和/或降解PFAS的功效和程度 在UV照射和/或H2O2暴露下。我们将鉴定PFAS降解产物，并阐明 相关的化学降解途径、动力学和机制。 目的2：评估PFAS的生物降解和完全矿化的功效， 产品通过丰富的微生物培养。混合厌氧微生物群落，包括已知的 脱卤剂将与一系列短链和长链未经处理和纳米材料处理的PFAS一起培养 以测量PFAS的去除功效和矿化。微生物群落结构和活性将 通过已知还原性脱卤酶基因的16s rRNA基因丰度和转录水平测量。 宏基因组学和转录组学将被应用于阐明微生物基因组和还原酶 参与PFASs生物降解的途径。 目标3：进行分子建模，以发现，检测和完善酶的生物降解， 结构多样的PFAS。包括分子对接和分子动力学在内的计算机工具已经表明， 识别PFAS-生物分子相互作用的强大潜力，可以为我们了解PFAS提供信息 毒理学和毒理动力学。在这里，分子建模方法将用于识别强 结构多样的PFAS和酶之间的相互作用，已显示出降解的潜力， 持久性卤化物质。PFASs和这些氨基酸残基之间的特异性相互作用 将确定酶;战略，包括社区组成和定向酶进化，将 研究允许调节分子相互作用以改善PFAS的降解性。 预期结果：我们的综合方法具有极大的潜力，以促进我们对PFAS的理解 氧化还原转化机制和生物降解途径。通过结合我们在纳米材料方面的专业知识， 设计，微生物学，化学表征和分子建模，我们将使设计一个 协同系统，以完全降解，脱氟和矿化各种PFAS。这款新的纳米- 生物修复方法有潜力纳入和应用在两个PFAS的处理列车- 受污染的地下水和饮用水源。关于全氟辛烷磺酸降解机制的知识， 分子水平将大大促进这类普遍存在的环境修复。 这些化学品是有害的，可被用于防止人体进一步接触这些具有生物累积性的危险化学品。

ABSTRACT Global public health concern is growing over per- and polyfluoroalkyl substances (PFASs) toxicity, environmental persistence, and potential to bioaccumulate in humans and wildlife. Nearly every person who has been tested for PFASs shows measurable levels in their blood resulting from contamination of the environment and continued use in consumer products and industrial applications. In particular, drinking water appears to be the major source of PFAS exposure for people living near contaminated sites. Importantly, some PFASs have been linked to liver damage, developmental impacts, and several cancers (e.g., kidney, testicular). Environmental remediation is urgently needed, but efforts are hampered by the extreme persistence of the carbon-fluorine bond. Biodegradation typically involves only the non-fluorinated components of polyfluorinated PFASs, resulting in the creation of shorter-chain perfluorinated acids that are more persistent and mobile. Complete mineralization has not been demonstrated. Abiotic treatment technologies can be more effective but require extremely high energy inputs, and the degradation mechanisms are poorly understood. There is a critical need for a treatment technology with lower energy requirements, and for enhanced degradation pathways that efficiently mineralize PFASs without formation of perfluorinated acids that persist after treatment. The overarching goal of this proposal is to develop an innovative nanomaterial-biological strategy to tackle the challenge of PFAS biodegradation. Our central hypothesis is that pretreatment by tailored nanomaterials can facilitate transformation of structurally diverse PFASs to achieve more efficient and complete biodegradation. Our previous work has shown that functionalized nanohybrid catalysts incorporating reduced graphene oxide (rGO) and nano zerovalent iron (nZVI) can successfully initiate degradation of long-chain PFASs. Here, we will employ this abiotic transformation as an innovative pretreatment to unlock the biodegradation of PFASs. Leveraging our expertise in molecular modeling and ‘omics’ techniques, we will test and tailor the ability of microbial communities to more efficiently degrade pretreated PFASs and their initial degradation products. All degradation products will be characterized by high-resolution mass spectrometry and 19F-nuclear magnetic resonance spectroscopy to reveal the mechanisms that enable this nano-bioremediation strategy. This research will tackle a pressing environmental contamination problem with three complementary specific aims: Aim 1: Synthesize multifunctional redox-active nanohybrid materials and evaluate their catalytic properties for PFAS degradation (dehalogenation, degradation of long-chains to short-chains). We will synthesize and characterize two multifunctional and hierarchical carbon-metal nanohybrids: (i) redox-active reduced graphene oxide nano zerovalent iron (rGO–nZVI) and (ii) photocatalytic rGO-nZVI- titanium dioxide (TiO2) or rGO-nZVI-TiO2, and test the efficacy and extent to which they can transform and/or degrade PFASs under UV irradiation and/or H2O2 exposure. We will identify the PFAS degradation products and elucidate the associated chemical degradation pathways, kinetics, and mechanisms. Aim 2: Assess the efficacy of biodegradation and complete mineralization of PFASs and degradation products by enriched microbial cultures. Mixed anaerobic microbial communities that include known dehalogenators will be cultured with a range of short- and long-chain untreated and nanomaterial-treated PFASs to measure the removal efficacy and mineralization of PFASs. Microbial community structure and activity will be measured by 16s rRNA gene abundance and transcription levels of known reductive dehalogenases genes. Metagenomics and transcriptomics will be applied to elucidate microbial genomes and reductive defluorination pathways that are involved in PFASs biodegradation. Aim 3: Perform molecular modeling to discover, detect, and refine enzymatic biodegradation for structurally diverse PFASs. In silico tools, including molecular docking and molecular dynamics, have shown powerful potential for identifying PFAS-biomolecule interactions that can inform our understanding of PFAS toxicokinetics and toxicodynamics. Here, molecular modeling approaches will be used to identify strong interactions between structurally diverse PFASs and enzymes that have shown potential for degradation of persistent halogenated substances. The specific interactions between PFASs and amino acid residues in these enzymes will be identified; strategies, including community composition and directed enzyme evolution, will be investigated to allow tuning of molecular interactions to improve degradability of PFASs. Expected Outcomes: Our integrative approach has significant potential to advance our understanding of PFAS redox transformation mechanisms and biodegradation pathways. By combining our expertise in nanomaterial design, microbiology, chemical characterization, and molecular modeling, we will enable the design of a synergistic system to completely degrade, defluorinate, and mineralize diverse PFASs. This novel nano- bioremediation approach has the potential for inclusion and application within the treatment train for both PFASs- contaminated groundwater and drinking water sources. Knowledge on the PFASs degradation mechanisms at the molecular level will substantially advance the environmental remediation of this ubiquitous class of contaminants, and prevent further human exposure to these bioaccumulative and hazardous chemicals.